Dermatopathology
Dermatopathology is the pathology of skin.
Pathology is a significant part of dermatology and dermatologists spend five years in residency. So, it is a huge area.
Layers of the skin
- Epidermis - outer most layer, avascular, separated from dermis by a basement membrane, epithelial tissue.
- Dermis - below the epidermis, vascular, separated from the epidermis by a basement membrane, connective tissue.
- Subdermis - below the dermis, connective tissue.
Layers of epidermis
Epidermis layers - from the surface to epidermal-dermal junction:
- Stratum corneum.
- Stratum lucidum.
- Present only in "thick" skin.[1]
- Stratum granulosum.
- Stratum spinosum (aka prickle layer).
- Stratum basale (germinativum).
Mnemonic: Corn Lovers Grow Several Bales.
Adnexal structures
The top five structures of the skin:[2]
| Structure / Attribute | Histomorphology | Function | IHC | Other | Image |
| Eccrine gland | clusters of tubular structures, pale cytoplasm | thermoregulation (cooling) | CK7+, CEA+, CAM5.2+, EMA+ | ? | ? |
| Apocrine gland | apical snouts, tubular structures | ear wax, body odor | ? | ? | ? |
| Sebaceous gland | clusters of cells side-by-side, pale fluffy cytoplasm | grease hair, sexual lubrication | ? | assoc. with hair follicle | ? |
| Hair follicle | linear structure | keep individual warm | ? | assoc. with sebaceous glands | ? |
| Nail | epidermal structure | ? look pretty | ? | ? | ? |
Ducts vs. glands:[3]
- Eccrine glands - spindle-shaped myoepithelial cells surround luminal cells.
- Eccrine ducts - cuboidal type subepithelial cells.
Common terms
- Acanthosis = thickening of the prickle layer (stratum spinosum) of epidermis.[4]
- Parakeratosis = retention of nuclei in the stratum corneum, normal in mucous membranes
- Dyskeratosis = abnormal keratinization, often refers to keratinization below the stratum granulosum; keratinization above may be abnormal (dependent on body site).
- Spongiosis = epidermal intercellular edema;[5] cells appear to have a clear halo around 'em.
Images:
Skin diseases
Cancer
Skin cancer is very common. The basic DDx of a malignant skin lesion is:
- Squamous cell carcinoma.
- Basal cell carcinoma.
- Malignant melanoma.
- Metstases.
Non-malignant disease
Non-malignant skin disease is common. It is the domain of dermatologists. It can be scary for general anatomical pathologist because the differential diagnosis is often broad, and, it's generally not something the general anatomical pathologist sees a lot of.
Bullous diseases, e.g. pemphigus vulgaris, is dealt with in the bullous disease article.
Presentations
Leukoplakia
DDx:[6]
- Vitiligo (loss of pigment).
- Inflammation.
- Chronic dermatitis.
- Psoriasis.
- Neoplasia.
- Vulvar intraepithelial neoplasia.
- Paget disease.
- Invasive carcinoma.
- Other.
Skin disease and systemic conditions
References
- ↑ Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 1. ISBN 978-0443066542.
- ↑ Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 4-8. ISBN 978-0443066542.
- ↑ HJ. 27 Feb 2009.
- ↑ http://dictionary.reference.com/browse/acanthosis
- ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 1230. ISBN 0-7216-0187-1.
- ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 1065. ISBN 0-7216-0187-1.
- ↑ http://www.emedicine.com/derm/topic1.htm [1]
- ↑ TN07 D23.
- ↑ TN07 D23.